US Bridges

Heron RD over Cabinet Gorge Res 049

Good

Sanders County, Montana · 1M W Heron · Structure no. 000000000004323

Built
2017
8 years old
Condition
Good
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
767 ft
3 main spans
Daily traffic
539
2023 count
Owner
County
County Highway Agency

About this bridge

Heron RD over Cabinet Gorge Res 049 is a steel continuous stringer/multi-beam or girder carrying Heron RD over Cabinet Gorge Res 049 in Sanders County, Montana. It was built in 2017, so it is 8 years old, younger than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 539 vehicles a day, roughly 3% of them trucks, projected to reach 577 by 2043. The structure is 767 ft (233.9 m) long and 33 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

Open in Google Maps
CarriesHeron RD
CrossesCabinet Gorge Res 049
Location1M W Heron
RouteCounty Highway 45004
CountySanders County
StateMontana
Coordinates48.06833, -115.97917
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27 US tons
Inventory rating21.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length767 ft (233.9 m)
Longest span375 ft (114.3 m)
Deck width33 ft (10.2 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic539 (2023)
Projected traffic577 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed31.7 mi (51 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.5 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Heron RD over Cabinet Gorge Res 049 built?

It was built in 2017, making it 8 years old in 2025.

What condition is Heron RD over Cabinet Gorge Res 049 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.

How much traffic does Heron RD over Cabinet Gorge Res 049 carry?

About 539 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Heron RD over Cabinet Gorge Res 049?

The structure is 767 ft (233.9 m) long with a longest span of 375 ft (114.3 m) and a deck 33 ft wide.

Who owns Heron RD over Cabinet Gorge Res 049?

It is owned by the County Highway Agency.